Preheat your oven to 350°F (175°C). Grease a 9x13-inch baking dish with butter or nonstick spray.

Bring a large pot of salted water to a boil and cook the egg noodles for 6-7 minutes until al dente. They should still have a slight bite since they'll continue cooking in the oven. Drain and set aside.

In a large mixing bowl, whisk together the cream of chicken soup, sour cream, and milk until completely smooth. Add the garlic powder, onion powder, salt, and pepper. Taste and adjust seasoning if needed.

Add the shredded rotisserie chicken, cooked noodles, and thawed peas and carrots to the sauce. Stir gently but thoroughly until everything is evenly coated. Fold in 1 cup of the cheddar cheese, reserving the remaining 1/2 cup for topping.

Transfer the mixture to your prepared baking dish and spread it into an even layer. Sprinkle the remaining cheddar cheese over the top.

In a small bowl, toss the crushed butter crackers with the melted butter until well combined. Scatter this golden mixture over the cheese layer.

Bake uncovered for 30-35 minutes until the casserole is bubbling around the edges and the cracker topping is golden brown. If top browns too quickly, tent loosely with foil.

Let it rest for 5-10 minutes before serving to allow the sauce to thicken.